The youngest layer of secondary xylem in the wood of a dicot stem is located just:

Each annual ring consists of two bands of .........

What is the commercial source of cork? How is it formed in the plant?

Annual rings are bands of .........

Read the different components from $(i)$ to $(iv)$ in the list given below and tell the correct order of the components with reference to their arrangement from outer side to inner side in a woody dicot stem.
$(i)$ Secondary cortex $(ii)$ Wood $(iii)$ Secondary phloem $(iv)$ Phellem
The correct order is:

Secondary xylem and phloem in dicot stem are produced by